In recent years power tools often include a power-tool battery pack. The power tool battery pack is attachable to and detachable from a main body of a power tool and functions as a power supply for the power tool. Such a power-tool battery pack generally comprises a battery main body and a case that houses the battery main body. The battery main body may comprise, for example, a plurality of rechargeable battery cells and a circuit board electrically connected to the battery cells for controlling charging and discharging of the battery cells. When the amount of charge in such a battery pack falls below a certain level or threshold, the power-tool battery pack is detached from the tool main body and then charged using a specialized charger. After being charged by the specialized charger, the power-tool battery pack is once again mounted onto the tool main body and used as the power-tool power supply.
One known type of power-tool battery pack is mountable by sliding it relative to the tool main body, the specialized charger, or the like. These power-tool battery packs are provided: with a sliding-guide structure to facilitate the slide mounting and with connection terminals that are electrically connectable to a counterpart side by performing the slide mounting as shown, for example in Japanese Laid-open Patent Publication 2001-57204 and its family member U.S. Pat. No. 6,350,149. Specifically, the tool main body and the specialized charger, for example, may be provided with plate-shaped male terminals, and the power-tool battery pack may be provided with female terminals that form an electrical connection with the male terminals when the male terminals are slidingly inserted into the female terminals.